Organic light emitting display device

ABSTRACT

An organic light emitting display device includes a plurality of pixels, each of the plurality of pixels including: a first sub-pixel configured to emit light of a first color; a second sub-pixel configured to emit light of a second color that is different from the first color; a third sub-pixel configured to emit light of a third color that is different from the first and second colors; and a transmission sub-pixel configured to selectively transmit external light in response to an electrical signal.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/849,447, filed Sep. 9, 2015, which is a continuation of U.S. patentapplication Ser. No. 13/975,265, filed Aug. 23, 2013, now U.S. Pat. No.9,159,295, which claims priority to and the benefit of Korean PatentApplication No. 10-2013-0014972, filed Feb. 12, 2013, the entire contentof both of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments of the present invention relate to an organic light emittingdisplay device.

2. Description of the Related Art

Organic light emitting display devices are being widely applied topersonal portable devices such as MP3 players, mobile phones, and TVsdue to their superior characteristics such as wide viewing angles, highcontrast, fast response speed, and low power consumption. Such anorganic light emitting display device has a self-emission property, andthus, an additional light source is not necessary, unlike a liquidcrystal display (LCD) device, and therefore a thickness and a weight ofthe organic light emitting display device may be reduced. Also, anorganic light emitting display device may be formed as a transparentdisplay device by including transparent thin film transistors (TFTs) ororganic light emitting diodes therein or by forming a transmissionregion (or transmission window) that is separate from pixel regions.

However, such a transparent organic light emitting display device has afixed transmittance so as not to meet the demand of a user who wants toadjust a transmittance of the organic light emitting display device.

SUMMARY

Embodiments of the present invention provide an organic light emittingdisplay device capable of adjusting a transmittance thereof.

According to an aspect of the present invention, there is provided anorganic light emitting display device including a plurality of pixels,each of the plurality of pixels including: a first sub-pixel configuredto emit light of a first color; a second sub-pixel configured to emitlight of a second color that is different from the first color; a thirdsub-pixel configured to emit light of a third color that is differentfrom the first and second colors; and a transmission sub-pixelconfigured to selectively transmit external light in response to anelectrical signal.

The first, second, and third sub-pixels may respectively include a firstsub-pixel electrode, a second sub-pixel electrode, and a third sub-pixelelectrode that are separate from each other, and the transmissionsub-pixel includes a transmission sub-pixel electrode that is separatefrom the first, second, and third sub-pixel electrodes.

The organic light emitting display device may further include: a firstdriving circuit, a second driving circuit, and a third driving circuitthat are electrically coupled to the first, second, and third sub-pixelelectrodes, respectively; and a switching line electrically coupled tothe transmission sub-pixel electrode.

The organic light emitting display device may further include: a firstdriving circuit, a second driving circuit, and a third driving circuitthat are electrically coupled to the first, second, and third sub-pixelelectrodes, respectively; and a transmission driving circuitelectrically coupled to the transmission sub-pixel electrode.

The transmission driving circuit may be at the transmission sub-pixel.

The transmission driving circuit may be at one of the first, second, andthird sub-pixels adjacent the transmission sub-pixel.

The organic light emitting display device may further include anopposite electrode at each of the plurality of pixels and facing thefirst, second, and third sub-pixel electrodes and the transmissionsub-pixel electrode.

The transmission sub-pixel may be configured to transmit the externallight when the electrical signal is not applied, and to blocktransmission of the external light when the electrical signal isapplied.

The transmission sub-pixel may be configured to transmit the externallight when the electrical signal is not applied, and to emit light ofone of the first, second, and third colors when the electrical signal isapplied.

The transmission sub-pixel may be configured to transmit the externallight when the electrical signal is not applied, and to emit light of afourth color that is different from the first, second, and third colorswhen the electrical signal is applied.

Each of the pixels may further include a fourth sub-pixel that isconfigured to emit light of a fourth color that is different from thefirst, second, and third colors.

According to another aspect of the present invention, there is providedan organic light emitting display device including a plurality ofpixels, each of the plurality of pixels including: an emission sub-pixelconfigured to display an emission image; and a transmission sub-pixelconfigured to selectively display a transmission image by external lighttransmitted through the transmission sub-pixel.

The emission sub-pixel may include an emission sub-pixel electrode, andthe transmission sub-pixel may include a transmission sub-pixelelectrode.

The organic light emitting display device may further include: anemission driving circuit electrically coupled to the emission sub-pixelelectrode; and a switching line electrically coupled to the transmissionsub-pixel electrode.

The organic light emitting display device may further include: anemission driving circuit electrically coupled to the emission sub-pixelelectrode; and a transmission driving circuit electrically coupled tothe transmission sub-pixel electrode.

The transmission driving circuit may be at the transmission sub-pixel.

The transmission driving circuit may be at the emission sub-pixeladjacent to the transmission sub-pixel.

The organic light emitting display device may further include anopposite electrode at each of the plurality of pixels and facing theemission sub-pixel electrode and the transmission sub-pixel electrode.

The transmission sub-pixel may be configured to display the transmissionimage when an electrical signal is not applied and not to display thetransmission image when the electrical signal is applied.

The transmission sub-pixel may be configured to display the transmissionimage when an electrical signal is not applied and to display theemission image when the electrical signal is applied.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and aspects of the present invention willbecome more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 is a cross-sectional view of an organic light emitting displaydevice according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of an organic light emitting displaydevice according to another embodiment of the present invention;

FIG. 3 is a plan view of a pixel in the organic emission unit shown inFIG. 1 and FIG. 2;

FIG. 4 is a cross-sectional view of the pixel taken along the line IV-IVof FIG. 3;

FIG. 5 is a plan view of the pixel of FIG. 3 in more detail;

FIG. 6 is a diagram schematically showing operations of an organic lightemitting display device including the pixel shown in FIG. 5;

FIG. 7 is a plan view showing another example of the pixel shown in FIG.3;

FIG. 8 is a plan view showing another example of the pixel shown in FIG.3;

FIG. 9 is a diagram schematically showing operations of an organic lightemitting display device including the pixel of FIG. 8;

FIG. 10 is a plan view showing a pixel in another example of the organicemission unit shown in FIG. 1 and FIG. 2; and

FIG. 11 is a plan view showing a pixel in another example of the organicemission unit shown in FIG. 1 and FIG. 2.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described indetail below with reference to accompanying drawings. As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

FIGS. 1 and 2 are cross-sectional views of organic light emittingdisplay devices according to different embodiments of the presentinvention.

Referring to FIG. 1, the organic light emitting display device 10 of thepresent embodiment includes an organic emission unit 2 formed on asurface of a substrate 1, and a sealing unit 3 for sealing the organicemission unit 2.

According to the embodiment shown in FIG. 1, the sealing unit 3 mayinclude a sealing substrate 31. The sealing substrate 31 may be formedof a transparent glass substrate or a transparent plastic substrate soas to display images from the organic emission unit 2. The sealingsubstrate 31 may also reduce (or prevent) external air and moisture frominfiltrating into the organic emission unit 2.

Edges of the substrate 1 and the sealing substrate 31 are coupled toeach other by a sealing material (or sealant) 32 so that a space 33between the substrate 1 and the sealing substrate 31 may be sealed.Moisture absorbent or a filling material may be located in the space 33.

Instead of using the sealing substrate 31, as shown in FIG. 2, a thinsealing film 34 may be formed on the organic emission unit 2 to protectthe organic emission unit 2 from external air. The sealing film 34 mayhave a structure in which a layer formed of an inorganic material suchas silicon oxide (e.g., SiO₂) or silicon nitride (e.g., Si₃N₄) and alayer formed of an organic material such as epoxy or polyimide arealternately formed. However, embodiments of the present invention arenot limited thereto, and a sealing structure formed of a transparentthin film may be used as the sealing film 34.

The organic light emitting display devices according to the embodimentsshown in FIGS. 1 and 2 may be realized as a bottom emission type thatdisplays images toward the substrate 1, a top emission type thatdisplays images toward the sealing substrate 31 or the sealing film 34,or a dual-emission type that displays images toward both the substrate 1and the sealing substrate 31 or toward both the substrate 1 and thesealing film 34.

Such an organic light emitting display device 10 may include a lightemission region and a light transmission region so as to realize atransparent and/or see-through display device.

The organic emission unit 2 shown in FIG. 1 or FIG. 2 includes aplurality of pixels for displaying images. FIG. 3 is a plan view of apixel P in the organic emission unit 2 shown in FIG. 1 and/or FIG. 2.

Each of the pixels includes emitting sub-pixels E for realizing lightemission images, and a transmission sub-pixel 25 forming a transmissionregion T so as to transmit external light to form a transmission image.

The emission sub-pixels E may include a first sub-pixel 21, a secondsub-pixel 22, and a third sub-pixel 23. The first sub-pixel 21 emitslight of a first color, the second sub-pixel 22 emits light of a secondcolor, and the third sub-pixel 23 emits light of a third color. Thesecond color is different from the first color, and the third color isdifferent from the first color and the second color. The first throughthird colors may be three different kinds of colors for realizing whitelight, for example, they may be red, green, and blue according toembodiments of the present invention.

The transmission sub-pixel 25 forming the transmission region T may beadjacent to the first through third sub-pixels 21, 22, and 23. In FIG.3, one transmission sub-pixel 25 forms the transmission region T;however, embodiments of the present invention are not limited thereto,that is, a transmission sub-pixel adjacent to the first sub-pixel 21,another transmission sub-pixel adjacent to the second sub-pixel 22, andanother transmission sub-pixel adjacent to the third sub-pixel 23 may belocated independently (e.g., separated or spaced) from each other.

The transmission sub-pixel 25 is configured to selectively transmitexternal light (e.g., allows external light to pass through) accordingto application of an electric signal.

FIG. 4 is a cross-sectional view of the pixel taken along the line IV-IVof FIG. 3.

The first sub-pixel 21 includes a first sub-pixel electrode 211, a firstemission layer 212 located on the first sub-pixel electrode 211, and anemission opposite electrode 261 located on the first emission layer 212.

The transmission sub-pixel 25 includes a transmission sub-pixelelectrode 251, a transmission adjusting layer 252 located on thetransmission sub-pixel electrode 251, and a transmission oppositeelectrode 262 located on the transmission adjusting layer 252. Thetransmission opposite electrode 262 may be electrically connected to theemission opposite electrode 261, for example, the transmission oppositeelectrode 262 and the emission opposite electrode 261 may be coupled toeach other to form one opposite electrode 26.

The first sub-pixel electrode 211 and the transmission sub-pixelelectrode 251 may be located on the substrate 1 independently (e.g.,separately) from each other.

An insulating layer 110 is formed on the substrate 1 so as to coveredges of the first sub-pixel electrode 211 and the transmissionsub-pixel electrode 251, and the first sub-pixel electrode 211 and thetransmission sub-pixel electrode 251 are exposed through openings (orgaps) of the insulating layer 110.

The first emission layer 212 and the transmission adjusting layer 252are formed on the exposed portions of the first sub-pixel electrode 211and the transmission sub-pixel electrode 251, and the opposite electrode26 is formed on the first emission layer 212, the transmission adjustinglayer 252, and the insulating layer 110.

The substrate 1 may include driving circuit units (or driving circuitsor drivers) that are electrically connected to the sub-pixel electrodes.Each of the driving circuit units may include at least a thin filmtransistor (TFT) and a capacitor.

FIG. 5 is a plan view of the pixel P shown in FIG. 3 in more detail.

The first sub-pixel 21, the second sub-pixel 22, and the third sub-pixel23 respectively include the first sub-pixel electrode 211, the secondsub-pixel electrode 221, and the third sub-pixel electrode 231, whichare independent from each other. In addition, the transmission sub-pixel25 includes the transmission sub-pixel electrode 251 that is independentfrom the first sub-pixel electrode 211, the second sub-pixel electrode221, and the third sub-pixel electrode 231. The transmission sub-pixelelectrode 251 may be disposed (or located) adjacent to all of the first,second, and third sub-pixel electrodes 211, 221, and 231 as shown inFIG. 5.

The first sub-pixel 21, the second sub-pixel 22, and the third sub-pixel23 respectively include the first emission layer 212, the secondemission layer 222, and the third emission layer 232 that respectivelycover the first sub-pixel electrode 211, the second sub-pixel electrode221, and the third sub-pixel electrode 231. The transmission sub-pixel25 includes the transmission adjusting layer 252 that covers thetransmission sub-pixel electrode 251.

The opposite electrode 26 is formed to cover all of the pixel P, forexample, to cover the first, second, and third emission layers 212, 222,and 232, and the transmission adjusting layer 252. Although not shown inFIG. 5, the opposite electrode 26 may be formed to cover all of thepixels.

The first, second, and third sub-pixels 21, 22, and 23 may function asanodes, and the opposite electrode 26 may function as a cathode, or viceversa.

The first emission layer 212, the second emission layer 222, and thethird emission layer 232 may be organic emission layers, and mayrespectively include an organic emission material emitting red light, anorganic emission material emitting green light, and an organic emissionmaterial emitting blue light. Although not shown in FIG. 5, at least oneor more organic layers including a hole injection transport layer and/oran electron injection transport layer may be further disposed (orlocated) between the first, second, and third sub-pixels 21, 22, and 23and the opposite electrode 26. When the first, second, and thirdsub-pixels 21, 22, and 23 are anode electrodes and the oppositeelectrode 26 is a cathode electrode, an organic layer including the holeinjection transport layer for injecting and/or transporting the holesmay be disposed (or located) between the first, second, and thirdemission layers 212, 222, and 232 and the first, second, and thirdsub-pixels 21, 22, and 23, and an organic layer including the electroninjection transport layer for injecting and/or transporting theelectrons may be disposed (or located) between the first, second, andthird emission layers 212, 222, and 232, and the opposite electrode 26.The hole injection transport layer and the electron injection transportlayer may be common layers that may be formed to cover all the pixels ofthe organic emission unit 2.

The organic layers including the first emission layer 212, the secondemission layer 222, and the third emission layer 232 may be formed invarious ways, such as by vacuum deposition, printing, and/or laserthermal transfer methods.

The first sub-pixel electrode 211, the second sub-pixel electrode 221,and the third sub-pixel electrode 231 may be formed as transparentelectrodes, semi-transparent electrodes, or reflective electrodes thatmay include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide(ZnO), or indium (III) oxide (In₂O₃).

The opposite electrode 26 may be formed as a transparent electrode or asemi-transparent electrode including silver (Ag), magnesium (Mg),aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni),neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca),ytterbium (Yb), or a compound thereof. The opposite electrode 26 may beconfigured to transmit light by forming the compound as a thin film.

The first sub-pixel 21, the second sub-pixel 22, and the third sub-pixel23 may respectively include a first driving circuit unit (or firstdriving circuit or first driver) 214, a second driving circuit unit (orsecond driving circuit or second driver) 224, and a third drivingcircuit unit (or third driving circuit or third driver) 234. The first,second, and third driving circuit units 214, 224, and 234 may beelectrically coupled to the first sub-pixel electrode 211, the secondsub-pixel electrode 221, and the third sub-pixel electrode 231,respectively. Each of the first, second, and third driving circuit units214, 224, and 234 may include a thin film transistor and a capacitor.The first, second, and third driving circuit units 214, 224, and 234 maycontrol light emission images from the first sub-pixel 21, the secondsub-pixel 22, and the third sub-pixel 23.

The transmission sub-pixel 25 may include a transmission sub-pixelelectrode 251, a transmission adjusting layer 252, and a transmissionopposite electrode 262 (refer to FIG. 3) that are sequentially stacked.The transmission sub-pixel 25 may transmit external light when anelectric signal is not applied thereto, and may block the external lightwhen an electric signal is applied thereto, or vice versa. To do this,the transmission sub-pixel 25 may include an electrochromic system.

The transmission sub-pixel electrode 251 may be formed of the samematerial as that of the first, second, and third sub-pixel electrodes21, 22, and 23. The transmission adjusting layer 252 may be formed byusing an electrochromic material. The transmission opposite electrode262 may be formed integrally with the emission opposite electrode 261 toform the opposite electrode 26. However, embodiments of the presentinvention are not limited thereto; the transmission sub-pixel electrode251 and the transmission opposite electrode 262 may be formed of anelectrode material that is capable of adjusting a transmittance of thetransmission adjusting layer 252. Although not shown in the drawings,the transmission sub-pixel 25 may further include a transmissionopposite electrode patterned on the transmission sub-pixel 25 region.

As an example, the transmission sub-pixel electrode 251 and thetransmission opposite electrode 262 may be formed of metal oxide, forexample, nickel oxide (e.g., NiO) and tungsten oxide (e.g., W₂O₃),respectively. In addition, the transmission adjusting layer 252 disposed(or located) between the transmission sub-pixel electrode 251 and thetransmission opposite electrode 262 may be formed of a transparentelectrolyte. When a voltage is applied between the transmissionsub-pixel electrode 251 and the transmission opposite electrode 262,lithium ions leak out of the transmission sub-pixel electrode 251 thatis formed of the nickel oxide and move to the transmission oppositeelectrode 262 formed of the tungsten oxide via the transmissionadjusting layer 252, and accordingly, external light transmissionthrough the transmission sub-pixel 25 may be blocked. If a small amountof lithium is added when the transmission sub-pixel electrode 251 isformed, the color variation may occur faster in wider range.

As another example, the transmission sub-pixel electrode 251 may beformed of ITO and the transmission adjusting layer 252 may be formed ofan organic/metal hybrid polymer including iron (Fe) ions. In addition,the opposite electrode 26 may be formed to cover the transmissionadjusting layer 252.

When an oxidation voltage is applied to the transmission sub-pixelelectrode 251, metal ions in the organic/metal hybrid polymer areoxidated into trivalent form, a highest occupied molecular orbital(HOMO) level of the metal ions is lowered and a potential gap increases.Thus, absorption area is moved to an ultraviolet region, and thus, theorganic/metal hybrid polymer is recognized as colorless. Theorganic/metal hybrid polymer may represent various colors according tothe applied voltage by changing a kind of metal ions included therein.For example, the transmission sub-pixel 25 may display red, green, blue,and white according to the application of electric signals.

The transmission sub-pixel 25 may use various electrochromic devices.

As described above, because the transmission sub-pixel 25 selectivelyblocks transmission of the external light according to the applicationof electric signals, the transmission sub-pixel 25 may further include aswitching line 253 electrically coupled to the transmission sub-pixelelectrode 251 as shown in FIG. 5. The switching line 253 may be locatedadjacent to the transmission sub-pixel 25 in order not to interfere withthe external transmission through the transmission sub-pixel 25. Theswitching line 253, for example, may be disposed (or located) to crossover the first sub-pixel 21 and the third sub-pixel 23.

As such, because the transmission sub-pixel 25 selectively transmits theexternal light (e.g., allows the external light to pass through), afirst emission image I₁ is displayed from the emission sub-pixels E ofthe organic light emitting display device and a transmission image I₂obtained from the external light transmitting through the transmissionregions T is displayed as shown in FIG. 6(a), and accordingly, a usermay see both the first emission image I₁ and the transmission image I₂.In addition, as shown in FIG. 6(b), when the transmission sub-pixels 25selectively block the transmission of the external light, the firstemission image I₁ is only displayed from the emission sub-pixels E ofthe organic light emitting display device 10 so that the user may seethe first emission image I₁ only.

The transmission sub-pixels 25 may be configured to transmit externallight when the electric signal is not applied thereto, and to emit lightof a certain color when the electric signals are applied thereto. Here,the certain color may be one of the first through third colors, or maybe a fourth color that is different from the first through third colors.To do this, the transmission adjusting layer 252 may be formed of anorganic light emitting material or an electrochromic material asdescribed above. Alternatively, in other embodiments, materialtransmitting external light when the electric signals are applied andemitting light of a certain color when the electric signals are notapplied may be selected as the organic light emitting material.

In this case, the transmission sub-pixel 25 may further include atransmission driving circuit unit (or transmission driving circuit ortransmission driver) 254 that is electrically coupled to thetransmission sub-pixel electrode 251 as shown in FIG. 7. Thetransmission driving circuit unit 254 may be configured to make thetransmission sub-pixel 25 function as an emission sub-pixel displayingan emission image when the external light is not transmitted through thetransmission sub-pixel 25, like the operation of first through thirddriving circuit units 214 through 234. For example, in a case where thetransmission sub-pixel 25 emits one of red light, green light, bluelight, or white light when the external light is not transmitted throughthe transmission sub-pixel 25, the transmission sub-pixel 25 may be usedto represent a gray scale of the pixel P, with the first through thirdsub-pixels 21 through 23. Accordingly, white balance, color, andbrightness of the pixels P may be easily adjusted.

The transmission driving circuit unit 254 may be located in thetransmission sub-pixel 25 as shown in FIG. 7; however, embodiments ofthe present invention are not limited thereto. That is, as shown in FIG.8, the transmission driving circuit unit 254 may be located in one ofthe emission sub-pixels E adjacent to the transmission sub-pixel 25 sothat the external light transmittance of the transmission sub-pixel 25may not be degraded due to the transmission driving circuit unit 254.

When the transmission sub-pixels 25 selectively transmit the externallight, the first emission image I₁ is displayed from the emissionsub-pixels E of the organic light emitting display device 10 and theexternal light is transmitted through the transmission region T todisplay a transmission image I₂ as shown in FIG. 9(a), and thus, theuser may see both the first emission image I₁ and the transmission imageI₂. In addition, in a case where the transmission sub-pixels 25selectively block the external light and emit light of a certain color,a second emission image I₃ is displayed from the emission sub-pixel E ofthe organic light emitting display device 10 so that the user only seesthe second emission image I₃ as shown in FIG. 9(b). The second emissionimage I₃ may have increased (or improved) white balance, color, andbrightness when compared with the first emission image I₁ because thetransmission sub-pixel 25 functions as the emission sub-pixelrepresenting the gray scale.

FIG. 10 is a plan view showing a pixel P′ according to anotherembodiment in the organic light emission unit 2 shown in FIGS. 1 and 2.

The pixel P′ shown in FIG. 10 may further include a fourth sub-pixel 24in addition to the first through third sub-pixels 21 through 23 shown inFIG. 3. Full white light may be represented by the first through fourthsub-pixels 21 through 24 that respectively emit red light, green light,blue light, and white light. Other components may be the same as thoseof the previous embodiment, and thus, descriptions thereof may beomitted.

FIG. 11 is a plan view showing another example of a pixel P″ in theorganic light emission unit 2 shown in FIGS. 1 and 2.

As shown in FIG. 11, the transmission sub-pixel 25 is located adjacentto the third sub-pixel 23.

In this case, if the first through third sub-pixels 21 through 23respectively emit red light, green light, and blue light and thetransmission sub-pixel 25 emits green light according to the electricsignal, the pixel P″ may be configured as a PenTile Matrix when theexternal light is not transmitted therethrough, thereby increasing (orimproving) resolution of the image.

In the pixel P″ of FIG. 11, a fourth sub-pixel emitting white light maybe further disposed (or included) in addition to the first through thirdsub-pixels 21 through 23 emitting red light, green light, and bluelight, thereby increasing (or improving) white balance.

According to aspects of the present invention, the organic lightemitting display device capable of selectively controlling externallight transmission may be provided.

In addition, the white balance, the color, and the brightness of thepixels may be increased (or improved) in a non-transmission mode.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims, andequivalents thereof.

What is claimed is:
 1. An organic light emitting display devicecomprising a plurality of pixels, at least one of the pixels comprising:a first sub-pixel configured to display a color; and a second sub-pixelconfigured to control level of transparency in response to an electricsignal applied in the second sub-pixel.
 2. The organic light emittingdisplay device of claim 1, wherein the second sub-pixel comprises anelectrochromic material.
 3. The organic light emitting display device ofclaim 2, wherein the second sub-pixel comprises a first electrode, asecond electrode, and a transparency adjusting layer between the twoelectrodes.
 4. The organic light emitting display device of claim 3,wherein either the first electrode or the second electrode comprises aconductive metal oxide.
 5. The organic light emitting display device ofclaim 3, wherein the transparency adjusting layer comprises atransparent electrolyte.
 6. The organic light emitting display device ofclaim 3, wherein the transparency adjusting layer comprises anorganic/metal hybrid polymer.
 7. The organic light emitting displaydevice of claim 2, wherein the first sub-pixel comprises an organicemission layer.
 8. The organic light emitting display device of claim 1,further comprising an electrode extending from the first sub-pixel tothe second sub-pixel.
 9. The organic light emitting display device ofclaim 1, wherein the second sub-pixel is greater than double the size ofthe first sub-pixel.
 10. The organic light emitting display device ofclaim 1, further comprising a third sub-pixel and a fourth sub-pixel,wherein the first sub-pixel is configured to display a first color, thethird sub-pixel is configured to display a second color, and the fourthsub-pixel is configured to display a third color.
 11. The organic lightemitting display device of claim 10, wherein the first, second, third,and fourth sub-pixels are adjacent each other in a first direction. 12.The organic light emitting display device of claim 10, wherein thefirst, third, and fourth sub-pixels are adjacent each other in a firstdirection, and wherein the second sub-pixel is adjacent the first,third, and fourth sub-pixels in a second direction crossing the firstdirection.
 13. The organic light emitting display device of claim 12,wherein the first, third, and fourth sub-pixels are sequentiallyarranged in the first direction, wherein a distance between an outermostedge of the first sub-pixel and an outermost edge of the fourthsub-pixel in the first direction is substantially the same as a distancefrom a first edge of the second sub-pixel to an opposite second edge ofthe second sub-pixel in the first direction.
 14. The organic lightemitting display device of claim 10, further comprising a fifthsub-pixel configured to display a fourth color.
 15. The organic lightemitting display device of claim 14, wherein the first, second, third,fourth, and fifth sub-pixels are adjacent each other in a firstdirection.
 16. The organic light emitting display device of claim 14,wherein the first, third, fourth, and fifth sub-pixels are adjacent eachother in a first direction, and wherein the second sub-pixel is adjacentthe first, third, fourth, and fifth sub-pixels in a second directioncrossing the first direction.
 17. The organic light emitting displaydevice of claim 16, wherein the first, third, fourth, and fifthsub-pixels are sequentially arranged in the first direction, wherein adistance between an outermost edge of the first sub-pixel and anoutermost edge of the fifth sub-pixel in the first direction issubstantially the same as a distance from a first edge of the secondsub-pixel to an opposite second edge of the second sub-pixel in thefirst direction.